Power supply means for vacuum tubes



July 23, 1935.

R. REcHNiTzER 2,009,070

POWER SUPPLY MEANS FOR VACUUM TUBS Filed Jan. 26, 1953 zzgl Bv@ Mm ATTORNEY phase and magnitude that the hum note, resulting from variations of the anode potential, is

Patented July 23, l1.935

UNITED STATES PATENT OFFICE POWER SUPPLY MEANS Fon'. vAcUUM TUBES Rudolf Rechnitzer, Berlin, Germany, assignor to Telefunken Gesellschaft fr Drahtlose Telegraphie m. b. H., Berlin, Germany, a corporation of Germany lApplication JanuaryV 20, 1933, serial No. 653,559 In Germany November 28, 1931 1 Claim.

compensated. It would be next to conceivable to provide a circuit as shown in Figure 1 in which a resistance R1 is arranged between cathode and the plus pole of the source of potential and in which another resistance R2 is in the cathode supply line of the amplifier tube V. The sizes of the resistances R1 and R2 are adapted to the durchgriff (reciprocal value of the amplification factor Translator) of the amplifier tube in such manner that the following relation is approximately fullled: R2=D R1. VHowever such a circuit is unsuitable for the amplification of oscillations, since through the compensation, also the anode D. C. current is suppressed. In accordance with the present invention, the condensers C and C are connected in parallel to the resistances R1 and R2 respectively and the size of these condensers is in like manner determined by the relation C=D C. Therefore, in the circuit of the invention there is no unnecessarily high loading resistance for the useful anode A. C. current in the anode circuit, since the supply source is bridged by the capacity C between cathode and anode.

The feature of the compensating circuit of being independent of the frequency which would be affected, if only the condenser C were provided, is maintained by a balancing condenser C.

In order to prevent compensation of D. C. voltage, the resistance R2 according to the present invention, is bridged by a high ohmic potentiometer Rp and the grid biasing voltage is derived from a sliding contact. In order to prevent vpacitive device between the grid electrode and a lating device provided with anode, cathode and grid electrodes, an energizing circuit for said tube comprising a source of fluctuating uni-directional current, positive and negative terminals for said source, a voltage divider resistor connected be- 5 tween the positive and negativeterrninals of said source, a connection between the anode of the tube and a point of said voltage divider resistor,

a connection between the cathode anda point of the voltage divider resistor which is more nega- 1|)Y tive than the anode connecting point whereby the anode of the tube is maintained at a positive potential with respect to the cathode thereof, an alternating current connection including a capoint of said voltage divider which is more negative than the cathode connection point, said alternating current connection point and the anode connection point being made atl such points of the voltage divider resistor that the potential applied to the anode is opposite in phase and Inu times the potential applied to the grid electrode, a condenser shunting theportion of the voltage divider resistor between the cathode point and the alternating current connection and a condenser shunting the portion of the voltage divider resistor between the cathode connection point and the anode connection point, the ratio of the second shunting condenser and the rst-named shunting condenser being substantially equal to the ratio of the resistance of that portion of the voltage divider resistor between the cathode connection point and the anode connection point and the resistance of that portion of the voltage divider resistor between the cathode connection point and the alternating current grid connection point, a high ohmic potentiometer resistor shunted across that portion of the voltage divider resistor which is between the cathode connection point and the alternating'current grid connection point and a direct current connection including. an impedance device between the grid electrode of the tube and a point of said high ohmic potentiometer resistance which is positive with respect to the alternating current connection point and negative with respect to the cathode connection point, said last-named connection providing a gridA biasing potential for Ysaid tube. 

